High-adhesiveness metal finishing paint and preparation method thereof

Abstract

The invention relates to the technical field of metal surface photocureable coatings, and particularly discloses a high-adhesiveness metal finishing paint and a preparation method thereof. The invention relates to a high-adhesiveness metal finishing paint, which comprises the following components by weight: 18-25 parts of trifunctional polyester acrylate resin; 10 to 15 parts of hydroxy acrylic resin; 1-2 parts of phosphate ester; 15-25 parts of an active monomer; 2-3 parts of a photoinitiator; 0.5-1 part of a leveling agent; and 35-55 parts of a solvent. The high-adhesiveness metal finishing paint can be used for protecting the surface of a metal base material, the low-shrinkage low-functionality polyurethane acrylic resin is adopted as main body resin, the hydroxyl acrylic resin which does not participate in curing crosslinking is compounded to resist shrinkage, phosphate is introduced to increase corrosion to the metal base material, and the high-adhesiveness metal finishing paint has the advantages that the high-adhesiveness metal finishing paint can be used for protecting the surface of the metal base material; and the effect of relatively high adhesive force is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of light-curing coatings on metal surfaces, and more specifically, to a high-adhesion metal finishing varnish and a preparation method thereof. Background Art

[0002] After the surface of metal products is coated, "paint peeling" often occurs due to the low adhesion between the organic coating and the metal substrate. This not only affects the appearance quality of the product, but also brings about product safety issues.

[0003] Compared with traditional heat-curing or naturally drying coatings, UV radiation-cured coatings have the advantages of fast curing and less pollution. Therefore, they have been widely used in industrially developed countries for the protection and decoration of optical fibers, solder resists, wood, paper, glass, plastics and metal surfaces.

[0004] For photocuring metal coatings, effectively reducing shrinkage force is one of the ways to improve the adhesion between the coating and the metal substrate. Therefore, some companies use low-functional polyester acrylic resin as the main resin to reduce coating shrinkage, but the adhesion still needs to be further improved. Summary of the invention

[0005] In order to improve the adhesion of the coating on the surface of the metal substrate, the present application provides a high-adhesion metal finishing varnish and a preparation method thereof.

[0006] In the first aspect, the present application provides a high-adhesion metallic finish paint, which adopts the following technical solution: A high-adhesion metal finishing varnish comprises the following components in parts by weight: 18-25 parts of trifunctional polyester acrylate resin; 10-15 parts of hydroxy acrylic resin; 1-2 parts of phosphate ester; 15-25 parts of active monomer; 2-3 parts of photoinitiator; 0.5-1 part of leveling agent; 35-55 parts of solvent.

[0007] By adopting the above technical solution: trifunctional polyester acrylate resin and hydroxyl acrylic resin are used as the main film-forming body: trifunctional polyester acrylate resin is soft, has low shrinkage, and provides a good adhesion foundation. Compound hydroxyl acrylic resin has a large molecular weight and does not participate in light curing crosslinking, thereby significantly reducing shrinkage. Adding phosphate has a corrosive effect on the metal substrate, thereby significantly increasing the adhesion of the coating.

[0008] The above compound system improves the adhesion of the coating by reducing shrinkage and achieving surface corrosion of the metal substrate. The adhesion of the coating reaches level 1 after curing, and the adhesion after boiling in water can also meet certain usage requirements.

[0009] Optionally, the solvent includes ethyl ester, butyl ester and ethylene glycol ethyl ether.

[0010] By adopting the above technical solution: the combination of the three can effectively dissolve the components in the coating and play the role of adjusting the construction viscosity and construction state.

[0011] Optionally, the solvent includes the following components in parts by weight: Ethyl ester 20-30 parts; Butyl ester 10-15 parts; 5-10 parts of ethylene glycol ethyl ether.

[0012] Optionally, the leveling agent is BYK-333.

[0013] The active monomers include triethoxytrimethylolpropane triacrylate and hydroxyethyl methacrylate.

[0014] By adopting the above technical solution: triethoxy trimethylol triacrylate is used to adjust the construction viscosity and construction state, and hydroxyethyl methacrylate can reduce the internal stress of the coating, reduce shrinkage and provide adhesion.

[0015] Optionally, the active monomer includes the following components in parts by weight: 10-15 parts of triethoxytrimethylolpropane triacrylate; Hydroxyethyl methacrylate 5-10 parts.

[0016] By adopting the above technical solution: when the amounts of the two are within the above range, the prepared coating has the best adhesion and high curing efficiency.

[0017] Optionally, the topcoat varnish further comprises 1-sulfonate propyl-3-methylimidazolium chloride.

[0018] By adopting the above technical solution: after adding 1-sulfonic acid propyl-3-methylimidazolium chloride, the adhesion of the coating surface is significantly improved. The reason may be: Phosphate esters form coordination bonds between the phosphate groups they contain and metal cations to form a phosphide film to improve the adhesion between the coating and the metal substrate, and the presence of 1-sulfonate propyl-3-methylimidazolium chloride can promote the presence of more metal cations on the metal surface, thereby enhancing the effect of phosphate esters. Therefore, when phosphate esters and 1-sulfonate propyl-3-methylimidazolium chloride exist together, the adhesion of the coating is higher than that containing only phosphate esters.

[0019] Optionally, the weight ratio of the added amount of 1-sulfonic acid propyl-3-methylimidazolium chloride to the phosphate ester is 0.3-0.6:1.

[0020] By adopting the above technical scheme: when the addition amount of 1-sulfonic acid propyl-3-methylimidazolium chloride is within the above range, the adhesion of the prepared coating on the metal surface reaches level 0 after curing, and after being boiled in water at 70°C for 30 minutes, the adhesion remains at level 1.

[0021] In a second aspect, the present application provides a method for preparing a high-adhesion metallic finish varnish, using the following technical solution: A method for preparing a high-adhesion metal finish varnish comprises the following steps: S1, adding a photoinitiator, a leveling agent, and a phosphate ester into a solvent, dispersing them, and obtaining a mixed solution; S2. Add active monomer, trifunctional polyester acrylate resin and hydroxyl acrylic resin into the mixed solution and disperse them to obtain the product.

[0022] By adopting the above technical solution, the process has fewer steps, is simple and efficient, is conducive to industrial scale-up preparation of finishing varnish, and the prepared finishing varnish has better adhesion on the surface of the metal substrate.

[0023] In summary, this application has the following beneficial effects: 1. This application uses trifunctional polyester acrylate resin and hydroxyl acrylic resin as the main film-forming body. The hydroxyl acrylic resin does not participate in photocuring and cross-linking, resists shrinkage, and at the same time, the addition of phosphate has a corrosive effect on the metal substrate, so that the coating has excellent adhesion on the surface of the metal substrate after curing; 2. 1-sulfonic acid propyl-3-methylimidazolium chloride is also added in this application, which may further improve the adhesion of the coating by enhancing the interaction between the phosphate ester and the metal substrate; 3. The process of the present application has fewer steps, is simple and efficient, is conducive to the industrial scale-up of the preparation of topcoat varnish, and the prepared topcoat varnish has excellent adhesion on the metal surface. DETAILED DESCRIPTION

[0024] The present application is further described in detail below in conjunction with the examples. The sources of the components are as follows, except for the following special instructions, the components are commercially available: Trifunctional polyester acrylate resin, obtained from Changxing Chemical Industry, Taiwan, China, model DRE-504; Hydroxylated acrylic resin, purchased from Foshan Gaoming Tongde Chemical Co., Ltd., model AC1010-1; Triethoxy trimethylol propane triacrylate, sourced from Changxing, Taiwan, China, brand EM331; Hydroxyethyl methacrylate, sourced from Mitsubishi, Japan; Phosphate ester, purchased from Sartomer, USA, model CD9051.

[0025] Example 1 A high-adhesion metal varnish, the components and their corresponding weights are shown in Table 1, and is prepared by the following steps: S1. Add photoinitiator 184, leveling agent BYK-333 and phosphate ester to the solvent (ethyl ester), stir and mix at 500 rpm for 10 min to obtain a mixed solution; S2. Add active monomers (triethoxytrimethylolpropane triacrylate, hydroxyethyl methacrylate), trifunctional polyester acrylate resin and hydroxy acrylic resin to the mixed solution, stir and mix at a speed of 600 rpm for 40 min, then add butyl ester and ethylene glycol ethyl ether, stir and mix at a speed of 300 rpm for 20 min, and obtain.

[0026] Example 2 A high-adhesion metal varnish, the components and their corresponding weights are shown in Table 1, and is prepared by the following steps: S1. Add photoinitiator 184, leveling agent BYK-333 and phosphate ester to the solvent (ethyl ester), stir and mix at 500 rpm for 10 min to obtain a mixed solution; S2. Add active monomers (triethoxytrimethylolpropane triacrylate, hydroxyethyl methacrylate), trifunctional polyester acrylate resin and hydroxy acrylic resin to the mixed solution, stir and mix at a speed of 700 rpm for 40 min, then add butyl ester and ethylene glycol ethyl ether, stir and mix at a speed of 350 rpm for 15 min, and obtain.

[0027] Example 3 A high-adhesion metal varnish, the components and their corresponding weights are shown in Table 1, and is prepared by the following steps: S1. Add photoinitiator 184, leveling agent BYK-333 and phosphate ester to the solvent (ethyl ester), stir and mix at 500 rpm for 10 min to obtain a mixed solution; S2. Add active monomers (triethoxytrimethylolpropane triacrylate, hydroxyethyl methacrylate), trifunctional polyester acrylate resin and hydroxy acrylic resin to the mixed solution, stir and mix at a speed of 800 rpm for 40 min, then add butyl ester and ethylene glycol ethyl ether, stir and mix at a speed of 400 rpm for 10 min, and obtain.

[0028] Comparative Examples 1-3 A high-adhesion metal finish varnish, which is different from Example 2 in that the amounts of the components are different, as specifically shown in Table 1.

[0029] Table 1 Components and their weights in Examples 1-3 and Comparative Examples 1-3 (kg) Embodiment 4-6 A high-adhesion metal varnish, the components and their corresponding weights are shown in Table 2, and is prepared by the following steps: S1. Add photoinitiator 184, leveling agent BYK-333, phosphate, and 1-sulfonic acid propyl-3-methylimidazole chloride to the solvent (ethyl ester), and stir and mix at a speed of 500 rpm for 10 min to obtain a mixed solution; S2. Add active monomers (triethoxytrimethylolpropane triacrylate, hydroxyethyl methacrylate), trifunctional polyester acrylate resin and hydroxy acrylic resin to the mixed solution, stir and mix at a speed of 700 rpm for 40 min, then add butyl ester and ethylene glycol ethyl ether, stir and mix at a speed of 350 rpm for 15 min, and obtain.

[0030] Table 2 Components and weights in Examples 4-6 (kg) Components Example 4 Example 5 Example 6 Trifunctional polyester acrylate resin 21.5 21.5 21.5 Hydroxylated acrylic resin 12.5 12.5 12.5 Triethoxytrimethylolpropane triacrylate 12.5 12.5 12.5 Hydroxyethyl Methacrylate 7.5 7.5 7.5 Photoinitiator 184 2.5 2.5 2.5 Phosphate 1.5 1.5 1.5 1-Sulfopropyl-3-methylimidazolium chloride 0.45 0.75 0.9 BYK-333 0.75 0.75 0.75 Ethyl ester 25 25 25 Butyl Ester 12.5 12.5 12.5 Ethylene glycol ether 7.5 7.5 7.5 Performance Testing The zinc alloy surface was sprayed with the varnish prepared in the examples and comparative examples to a thickness of 12 μm, and baked at 50°C for 5 min. A high-pressure mercury lamp with a line power of 120 W / cm2 and a wavelength of 350 nm was used to irradiate the surface with a radiation dose of 600 mJ / cm2. 2 After drying and curing for 5 seconds, a test plate was obtained, and the test plate was subjected to the following performance tests. The test results are recorded in Table 3.

[0031] Adhesion test: 1. Test according to GB / T 9286-1998.

[0032] 2. Boil the test panel in water at 70°C for 30 minutes, and then test it according to GB / T 9286-1998.

[0033] Table 3 Performance test results Referring to Table 3, in Examples 1-3, trifunctional polyester acrylate resin, hydroxyl acrylic resin and phosphate are used, and the adhesion of the composite coating after curing on the metal substrate surface is level 1. After boiling in water at 70°C for 30 minutes, the adhesion drops to level 2, which meets the use requirements.

[0034] The difference between Comparative Examples 1-3 and Example 2 is that: Comparative Example 1 does not contain hydroxy acrylic resin, and the coating is not completely cured; Comparative Example 2 reduces the amount of phosphate ester, and the adhesion level decreases to varying degrees. Comparative Example 3 increases the amount of phosphate ester, and the adhesion does not change significantly. Considering the cost and other factors, Examples 1-3 are the best dosage range.

[0035] The difference between Example 4-6 and Example 2 is that the coating also includes 1-sulfonate propyl-3-methylimidazolium chloride, and the adhesion is improved to level 0. After boiling in water, the adhesion is maintained at level 1, and the adhesion is significantly improved. The reason may be that 1-sulfonate propyl-3-methylimidazolium chloride promotes the presence of more metal cations on the surface of the metal substrate to facilitate the chelation of the phosphate groups in the phosphate ester, thereby improving the effect of the phosphate ester and thus improving the adhesion of the coating.

[0036] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A high-adhesion metal finishing paint, characterized in that: The composition comprises the following components in parts by weight: 18-25 parts of trifunctional polyester acrylate resin; 10-15 parts of hydroxy acrylic resin; 1-2 parts of phosphate ester; 15-25 parts of active monomer; 2-3 parts of photoinitiator; 0.5-1 part of leveling agent; 35-55 parts of solvent.

2. The high-adhesion metallic finish paint according to claim 1, characterized in that: The solvents include ethyl esters, butyl esters and ethylene glycol ethyl ether.

3. The high-adhesion metallic finish paint according to claim 2, characterized in that: The solvent comprises the following components in parts by weight: Ethyl ester 20-30 parts; Butyl ester 10-15 parts; 5-10 parts of ethylene glycol ethyl ether.

4. The high-adhesion metallic finish paint according to claim 1, characterized in that: The leveling agent is BYK-333.

5. The high-adhesion metallic finish paint according to claim 1, characterized in that: The active monomers include triethoxytrimethylolpropane triacrylate and hydroxyethyl methacrylate.

6. The high-adhesion metallic finish paint according to claim 5, characterized in that: The active monomers include the following components in parts by weight: 10-15 parts of triethoxytrimethylolpropane triacrylate; Hydroxyethyl methacrylate 5-10 parts.

7. The high-adhesion metallic finish paint according to claim 1, characterized in that: The varnish also includes 1-sulfonic acid propyl-3-methylimidazolium chloride.

8. The high-adhesion metallic finish paint according to claim 7, characterized in that: The weight ratio of the added amount of the 1-sulfonic acid propyl-3-methylimidazolium chloride to the phosphate ester is 0.3-0.6:

1.

9. A method for preparing a high-adhesion metallic finish paint according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, adding a photoinitiator, a leveling agent, and a phosphate ester to a solvent, dispersing the mixture, and obtaining a mixed solution; S2. Add active monomer, trifunctional polyester acrylate resin and hydroxyl acrylic resin into the mixed solution and disperse them to obtain the product.

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